diff --git a/include/PSX/System/IOPorts/ioport.hpp b/include/PSX/System/IOPorts/ioport.hpp
index 1e9a7036..1aae0679 100644
--- a/include/PSX/System/IOPorts/ioport.hpp
+++ b/include/PSX/System/IOPorts/ioport.hpp
@@ -9,8 +9,9 @@ namespace JabyEngine {
         T value;
 
     public:
+        // decltype(this) instead of IOPort<T>* lead to wrong runtime behaviour somethow...
         constexpr T read() const {
-            return const_cast<const volatile decltype(this)>(this)->value;
+            return const_cast<const volatile IOPort<T>*>(this)->value;
         }
 
         template<typename...ARGS>
@@ -24,7 +25,7 @@ namespace JabyEngine {
         }
 
         constexpr void write(const T& value) {
-            const_cast<volatile decltype(this)>(this)->value = value;
+            const_cast<volatile IOPort<T>*>(this)->value = value;
         }
 
         // We keep this a POD so we will not add assignment operators anymore